In this article, we are going to tell you the methods of producing dried fruit and its evolution, so that you can have something to say about dried fruit and how to produce it, it is not a bad idea to stay with us until the end of this article:
Throughout his life, humans have always used many methods to prepare and produce food, dry fruit is one of these methods. Fruit drying is one of the oldest ways to preserve fruits for future use.
In countries where fruit production is high, but the demand and export of fruits is low, the best solution to preserve and prevent the fruits from spoiling is drying.
Of course, in order to have healthy and high-quality dried fruit, we must pay attention to the drying methods and the hygienic way of keeping it, in principle, correcting and improving the methods of fruit production and different care of it in increasing the quality of fruits. Dryness and increasing their export can be effective.
Principles of drying fruits
In order for your dried fruit to have the best quality, it is better to pay attention to the principles defined in the following text:
Selection of raw material
For the production of dried fruit, fruits should be selected that are less damaged during handling and operation before drying. Color stability and high percentage of raw fruit materials are effective in choosing the variety. It is usually better to use ripe fruits for drying.
Pick up and shipping
When picking fruits, it is better to use the same traditional method, i.e. hand picking, instead of industrial picking. You can use the fruits that are out of reach for manual picking by spreading the tent and shaking the branches that are placed on the tent. If you have a channel in the middle of the tent that can be opened and closed with a zipper, it will help a lot in gathering them.
Wash
The next step after collecting the fruits is to wash them, you must do this with clean and hygienic water. If you wash immediately after harvesting, it will remove possible toxins left on the fruit, remove dust, insects, pests and their eggs.
It is better to do the washing in large containers with half water and rinse the fruits after washing them completely. and dry completely.
Remove the extra parts
After washing, it is important to clean and separate the damaged parts, extra parts, skin and core of fruits such as apricots, peaches, apples and pears.
Cut and slice
In order for the fruits to dry better and faster, you should cut them in half, slice them or cut them into pieces. To do this, a knife and clean trays are necessary.
Preserving the color of dried fruits
Most of the fruits have a light color, but after being cut and cut into pieces, their color becomes cloudy due to exposure to the air and may become darker after drying completely. There are methods that can be used to produce dried fruit with beautiful color and soft texture.
Ways and methods of drying fruit
The contents mentioned above were all part of the principles of selection and how to prepare fruits for drying, in the following we will tell you the methods of drying fruits:
Sulfurization
Using sulfur is one of the most common ways of preparing dried fruits and producing fruit leaves. Sulfurization is usually done in two ways:
- smoking fruits with sulfur; Place the fruits in the tray without stacking them on top of each other, then put the trays on wooden boxes with holes or grooves that are slightly larger than the trays and smoke them. (Tunnels or smoking chambers are usually used for this purpose).
Tip:
The smoke from sulfur makes the dried fruits stay soft, slow to rot and their color does not darken. It also causes vitamins A and C to remain and preserve in fruits.
- Immersion in sulphurous solutions; The method of immersing in the solution is better than smoking because of its ease and speed. You can use ready-made sulfur solutions for this purpose, put sliced fruits in this solution for 5 minutes and halved fruits in this solution for 15 minutes. After that, you should wash the fruits and put them on net trays.
Use of vitamin C solution
To prevent fruits from browning or darkening, you should use vitamin C (ascorbic acid) solution, ascorbic acid is a healthy, safe and safe solution that you can safely use.
To do this, dissolve a tablespoon of vitamin C powder or a 3 gram tablet of it in two cups of water and make a solution from that, then put the fruits in it for 3 to 5 minutes and then dry the fruit. .
Use of fruit juice
In this method, fruit juices containing vitamin C are used to prevent the fruits from darkening. For this purpose, the juice of dried fruit and dried fruit is immersed in juices such as orange, lemon, pineapple, grape and barberry for 2 to 3 minutes. Of course, it goes without saying that some of the color and taste of the juices may spread to the dried fruits.
Dip in honey
For this method, you can make a liquid from honey and boiling water and then put the pieces of fruit in it for 3 to 5 minutes, honey helps to keep the color of the fruit.
Use of steam
In this method, boil water in a large container and put the fruits in a net on top of the container of boiling water. Steaming preserves the color of the fruit, but it may slightly change the taste and texture of the dried fruit. Make sure that when steaming, it should be done in such a way that the fruits do not sink into the boiling water, but the lid of the boiling water container should be closed during steaming.
Drying the fruits in the sun
The easiest and cheapest way to dry fruits is to put them in the sun, because of their sugar and acid content, fruits can easily dry in the sun. It is true that it is the cheapest method, but it has disadvantages as follows:
- Long drying time
- Reduction of fruit sugar due to respiration and evaporation
- Invasion of insects and dust, which has the possibility of spoiling the fruit.
Characteristics of trays and plates used for drying
You should place the trays and plates you want on bases so that the air can move around the fruit more easily and also the moisture is not transferred from the ground to the fruits. For this purpose, it is better for the plates to be made of metals such as aluminum or tin, because in this case, the plates will be heated enough under the sunlight and will cause the fruits to dry better and faster.
Iron, copper and aluminum trays are not suitable for drying fruits because iron rusts easily and its effect remains on the leaves, copper destroys vitamin C in the fruit, and aluminum causes the fruit to turn yellow and eat. .
To prevent insects from sticking to the surface of the dried fruit, it is better to use two nets, one for drying and the other to prevent insects from entering it.
Heat sources for drying fruits
Sunlight is considered as a heat source in drying fruit by the solar method. Drying under the weather takes time. To solve this problem, dryers are designed in which the temperature and air flow speed are increased by methods and the drying time of the fruit is shortened in them, so the risk of mold, spoilage and reduction in the quality of the produced product is reduced.
In these dryers, with the help of plates called solar energy collectors, which are usually made of metal and glass, the sun’s heat is transferred to the air, and the hot air enters the dryer chamber, where the fruit pieces are located.
In other types of dryers, the necessary heat to raise the air temperature is provided through electricity and placing thermal elements inside the dryer chamber. In this way, you should make sure that the temperature inside the dryer is not higher than 65 degrees Celsius.
Methods of eliminating pests and insects and their eggs in dried fruits
Because the product dried in the shade did not receive enough heat to destroy the insects and their eggs, Nesseh ensured the destruction of the insects and their possible eggs by performing an operation:
freezing method
The dried fruits are put in plastic bags for the freezer, then the bags are placed in the freezer at a temperature of -16 degrees Celsius or less for at least 48 hours so that possible pests and insects are destroyed by the cold.
thermal method
The fruits are poured into trays or shallow containers and then placed in a greenhouse with a temperature of about 65 degrees for 30 minutes so that pests and insects are destroyed by the heat.
balancing moisture
Fruits are not in the same condition when placed in the dryer or tray, so some parts of the fruit may have more moisture than others. After the fruits are dried, they are stored in large boxes at room temperature for 10 to 15 days and are turned over every few days to balance them.
Packaging and storage of dried fruits
Because dried fruits have the ability to absorb water, they absorb moisture from the environment quickly. It is better to keep them in a dry place. It is better not to pack dried fruits hot, pack them completely cold and then pack them. Because it causes the product inside the package to sweat and this complication is dangerous for mold growth.
Dried fruits should be kept in clean, dry and impervious packages against moisture and insects and as tight as possible. Glass containers, cardboard or strong and moisture-resistant boxes are suitable for packaging. Thick and strong plastic bags are also suitable, although they do not have much resistance to damage caused by insects and rodents.
Dried fruits and nuts should be stored in a cool and dark place. Depending on the type of dried fruit, these products can be stored between 4 and 12 months in suitable conditions.
In this regard, the temperature and humidity of the warehouse are very important, and the lower the temperature of the warehouse, the longer the storage time of the product. For example, if the storage temperature is 15 degrees, the product can be stored for up to one year. But at a temperature of 25 degrees, this time reaches about 6 months.
In order to prevent the attack of storage pests such as Indian moth and toothed louse, dry fruit storage warehouses should be disinfected every so often. For this purpose, use sublimation poisons that are made in the form of pills. These tablets are packed in airtight aluminum tubes.
Gas sublimation usually starts 1-2 hours after the pill is taken out of the container and lasts for 4.5-5 days on average. From these tablets, after the gas is decomposed, some aluminum hydroxide remains, which according to the manufacturer’s opinion is harmless.
Important points in drying fruits
Fresh and ripe fruits should be used for drying.
Washing the fruit before drying removes possible toxins left on the fruit and removes dust, insects and pests.
By performing operations such as sulphurizing, steaming, honey syrup and vitamin T solution, a product with a suitable color can be produced.
To evenly distribute moisture in dry fruits, they should be kept at room temperature for 10 to 15 days.
Dried fruits should be kept in clean, dry and impervious packages against moisture and insects.
Never use empty sacks of chemical fertilizers to store dried fruit.